In the formation of molded articles, it is often desired to integrate various preformed items into the molded article during the molding process. One common way of incorporating preformed items into a molded article is via insert molding. Insert molding involves first placing the preformed item into a desired location within a mold, and then adding a moldable material, such as a polymer, into the mold in such a manner that the polymer either contacts or surrounds at least part of the preformed item. As the moldable material sets, the preformed item is incorporated into the molded article.
Current insert molding techniques typically require the mold to be specially tooled to hold the preformed item in place during the molding process. Sometimes, this may involve forming mounting holes in the mold that are configured to accept complementary mounting pins on the preformed item. Such a mold may require expensive and complex tooling, which may add to the cost and complexity of the overall molding process. Furthermore, the completed molded article may have exposed tooling holes, or other visible defects, caused by the molding process. Correcting or hiding these defects may be time-consuming and expensive, and thus may increase the overall cost of the molding process. Additionally, this method may not be suitable for use with items to which the attachment of mounting pins may be difficult, such as fabric pieces or other thin, flexible items.
Exemplary molding methods and articles are disclosed in U.S. Pat. No. 3,390,482 to Holtvoight; U.S. Pat. No. 3,972,975 to Noda; U.S. Pat. No. 4,596,683 to Powell; U.S. Pat. No. 4,642,209 to Powell; U.S. Pat. No. 5,645,780 to Rinehart; U.S. Pat. No. 5,919,324 to Moffitt et al.; and U.S. Pat. No. 6,331,028 to O'Neill et al., the disclosures of which are hereby incorporated by reference. Other exemplary molded articles are disclosed in U.S. Pat. No. 4,028,845 to Licitis; U.S. Pat. No. 5,913,708 to Gross; and U.S. Pat. No. 6,050,875 to Lee, the disclosures of which also are hereby incorporated by reference.